/Engine/Source/Runtime/MovieScene/Public/EntitySystem/MovieSceneEntityFactory.h
Adds the definition for a child component. The helper methods above are easier and preferrable.
void DefineChildComponent ( [TInlineValue](API\Runtime\Core\Misc\TInlineValue)< [FChildEntityInitializer](API\Runtime\MovieScene\EntitySystem\FChildEntityInitializer) > && InInitializer )